In the medical and veterinary setting, the need may arise to rapidly infuse intravenous fluid into a subject. Saline and lactated ringers are examples of commonly used intravenous fluids. Such fluids may be used to maintain or elevate blood pressure and promote adequate perfusion. In the shock-trauma setting or in septic shock, fluid resuscitation is often first-line therapy to maintain or improve blood pressure.
Currently, a first responder, such as emergency medical technicians or military field medics, are known to administer intravenous fluids with a gravity drip, having a fluid bag, a fluid line, and an needle or intravenous catheter. When the needle or intravenous catheter is inserted into a subject, gravity causes the fluid to flow from the fluid bag, through the fluid line and needle, and into the subject. To increase the speed at which intravenous fluids are infused into the subject, the technician may apply pressure on the bag. Pressure may be applied by hand, by employing a blood pressure cuff, or other external pneumatic pressure device on the fluid bag itself.
Additionally, intraosseous (I.O.) lines have gained wider use in pediatric subjects, as well as adult subjects. Intraosseous infusion is a process of injection directly into the marrow of a subject's bone. Intraosseous lines often have a relatively slow rate of infusion.
There also exist several types of electronic pumps that infuse intravenous fluids. Such electronic pumps are often very costly and complex, and may require special training to operate. Further, such pumps may be delicate and not suited for field use. A first responder company will require several of these, adding to cost. Lastly, electronic pumps require a power source, such as a battery or wall socket, and may not necessarily be friendly to the environment.